Users can provide inputs to electronic devices using many different approaches. For example, an electronic device can include different input devices by which a user can interact with the electronic device. The input devices can include one or more switches, buttons, keys, actuators, or sensors (e.g., touch sensors), the actuation of which the electronic device can detect. Many of these input devices provide a binary input for user interaction in that the devices either register an input or they do not. For example, keyboards register an input only when a sufficient force is applied to a key to collapse a dome switch beneath a key. A dome switch is typically constructed by placing a deformable dome over a conductive contact pad on a circuit board. When a user presses down on the key, the dome collapses such that a conductive surface of the dome contacts the conductive contact pad, thereby actuating the dome switch. If an insufficient force is applied to the key, the dome does not collapse adequately and no input is registered. Likewise, both the force necessary to barely collapse the dome and the force far above that necessary to collapse the dome register as the exact same input.
Some applications and electronic devices may benefit from additional inputs beyond that provided strictly by binary input devices. For example, it may be advantageous for a user to be able to indicate an amount of force applied to an input device. For instance, a user could manipulate a screen element or other object in a first way with a relatively light touch or in a second way with a relatively more forceful touch.